Turkish authorities have issued an arrest warrant for a former officer of the U.S. Central Intelligence Agency (CIA) over suspected links to last year's failed coup.

An İstanbul prosecutor ordered the detention of Graham Fuller, ex-vice chairman of the CIA's National Intelligence Council and CIA officer in Turkey, on suspicion that he helped to plan the July 2016 coup attempt.

Turkish authorities believed resided in Turkey during the attempted coup, and left the country after it failed in which rogue soldiers commandeered tanks and helicopters in an attempt to oust Turkish President Tayyip Erdoğan.

The İstanbul Chief Public Prosecutor’s Office believes that Fuller obtained sensitive information for political and military espionage. He is also suspected of having contacts with CIA-linked Henri Barkey, the former director of the Middle East Program at the Woodrow Wilson International Center for Scholars. Barkey has been reportedly accused of organising and orchestrating the coup alongside other suspects.

CIA-linked Gülen network -led by U.S.-based Fethullah Gülen- was one of the masterminds of last years coup attempt.

Fuller previously said in a Huffington Post piece that he wrote a letter as a private citizen in support of Gülen's green card application in 2006 because he "did not believe that Gülen constituted a security threat to the US".

The move came after Iranian-Turkish gold trader Reza Zarrab with ties to President Erdoğan took the stand in federal court in Manhattan and testified that he paid jaw-dropping bribes to a government minister to grease the wheels of a scheme to evade U.S. sanctions against Iran. In his testimony, Zarrab implicated Erdoğan in a multi-billion-dollar gold-for-oil scheme allegedly designed to subvert the sanctions.